(1) Field of the Invention
The present invention relates to a recording quality evaluation method of an optical disk, and an optical disk storage system. More particularly, the present invention relates to a technology for evaluating the degradation of the quality of data recorded on an optical disk in a short time.
(2) Description of the Related Art
When data is recorded and stored in an optical disk for a long time, it is necessary to evaluate whether the quality of the recorded data is degraded over time. When quality degradation is detected, operations such as rewriting the data to another optical disk should be performed. The quality evaluation can determine the degree of degradation by reproducing and checking the data recorded on the optical disk. At this time, when all recorded data are checked as in the case of verify process performed at the time of recording, it takes too much time and is inefficient. Thus, there is a demand for a method of evaluating the quality in a short time.
In order to reduce the time of the verify process, the following methods have been proposed. JP-A No. 185477/2004 describes a method of performing the verify process at a predetermined time interval, and changing the time interval to perform the verify process according to the verify result. JP-A No. 181621/2009 describes a method of selecting a recording layer to perform a verification, and specifying a range to perform the verification based on the address located at the outermost periphery of the selected recording layer. JP-A No. 163881/2000 describes a method of searching the oldest information of all the information read from an optical disk, recording or reproducing the information on or from the original recording sector, and determining the quality state of the optical disk.